Department of Animal Sciences, Institute of Veterinary Medicine, Division of Microbiology and Animal Hygiene, Faculty of Agricultural Sciences, Georg-August-University, Burckhardtweg, Göttingen, Germany.
Transbound Emerg Dis. 2013 Apr;60(2):175-87. doi: 10.1111/j.1865-1682.2012.01336.x. Epub 2012 May 10.
Johne's disease is caused by Mycobacterium avium ssp. paratuberculosis (MAP) and has been recognized as an important bacterial infection in ruminants. Although MAP has been detected in semen and within the reproductive organs of bulls, the bacterial distribution and shedding patterns are currently not well characterized. Our investigation was performed to detect and quantify MAP in faeces, semen and blood samples repeatedly drawn from a naturally infected but asymptomatic 18-month-old German Simmental breeding bull candidate over a period of 3 years (June 2007-November 2010). Qualitative and quantitative polymerase chain reaction (PCR) techniques were used to correlate the presence and matrix-specific amounts of MAP. In total, 65 sampling dates were selected. Mycobacterium avium ssp. paratuberculosis was detected intermittently in all matrices with MAP-free intervals of up to 18 weeks by an IS900 semi-nested PCR. The number of MAP-positive results from semen and blood samples was higher than from faecal samples. A quantitative polymerase chain reaction detected the highest MAP contents in faeces (10(3) -10(6) MAP/g), while lower amounts were found in semen and blood samples (10(2) -10(5) MAP/ml). Although no significant agreement was calculated between the presence of MAP in faeces and blood, a statistically significant positive correlation between its occurrence in semen and blood was determined (r = 0.38, P < 0.05, n = 29). The present study contributes to a more detailed understanding of MAP distribution patterns in faeces, semen and blood of a subclinically infected breeding bull candidate. It highlights the possible role of breeding bulls as a source of MAP transmission and indicates the need for further monitoring and hygienic measures to prevent the spread of the infection via semen.
约翰氏病是由禽分枝杆菌副结核亚种（MAP）引起的，已被认为是反刍动物的一种重要细菌性感染。尽管已经在精液和公牛生殖器官中检测到了 MAP，但目前对细菌的分布和脱落模式还没有很好的描述。我们的研究旨在检测和定量分析一头自然感染但无症状的 18 月龄德国西门塔尔种公牛候选者的粪便、精液和血液样本中 MAP 的分布情况，该研究持续了 3 年（2007 年 6 月至 2010 年 11 月）。使用定性和定量聚合酶链反应（PCR）技术来关联 MAP 的存在和基质特异性数量。总共选择了 65 个采样日期。通过 IS900 半巢式 PCR，我们发现所有基质中 MAP 间歇性存在，MAP 阴性间隔长达 18 周。精液和血液样本中 MAP 阳性结果的数量高于粪便样本。定量 PCR 检测到粪便中 MAP 含量最高（10（3）-10（6） MAP/g），而精液和血液样本中的含量较低（10（2）-10（5） MAP/ml）。尽管在粪便和血液中 MAP 的存在之间没有计算出显著的一致性，但在精液和血液中 MAP 的发生之间确定了具有统计学意义的正相关关系（r = 0.38，P <0.05，n = 29）。本研究有助于更详细地了解亚临床感染的种公牛候选者粪便、精液和血液中 MAP 的分布模式。它突出了种公牛作为 MAP 传播源的可能作用，并表明需要进一步监测和卫生措施，以防止通过精液传播感染。
